Process for breaking petroleum emulsions



zyl alcohol may be used. Other alcohols which can be employed include tetrahydropyran-2- methanol and tetrahydrofurfuryl alcohol. My preference is to use aliphatic alcohols having at least 3 carbon atoms and preferably being watersoluble. This includes propyl alcohol, butyl alcohol, or amyl alcohol. In the case of butyl and amyl alcohols some of the isomers are watersoluble to the extent that they show solubility of a few percent at room temperature. Reference to the hydrocarbon group of such alcohols includes, of course, the derivatives of tetrahydropyran-2-methanol and tetrahydrofurfuryl alcohol even though there is an oxygen atom present. For the present purpose such radicals act as if they were entirely hydrocarbon in nature insofar that the presence of the oxygen atom contributes no objectionable property.

The oxypropylation, or for that matter the I treatment of such monohydric compounds with If for sake of simplicity the alcohol selected for oxypropylation is isopropyl alcohol the comparable derivative is indicated thus:

It has been pointed out previouslyl that such monohydric ether alcohols must be of fairly high molecular weight and thus the value of n in the two preceding formulas is Within-the range of approximately 12 to 80. My preference-is that the molecular weight of the product at this stage be within the range of 2000 to 3000. Such ether alcohols can be obtained by other means which are well known. For instance, they are commercially available, polypropylene glycol having molecular weightswithin the range of 1,000 to 3,000, or even higher. Such products can, of course, be etherized with suitable reactants such as dimethyl sulfate, diethyl sulfate, methylbenzene sulfonate, ethylbenzene sulfonate, propylbenzene sulfonate, or the like, to yield the corresponding ether alcohol. Other procedures are known also such as oxypropylation of the chlorohydrin followed by treatment with an alkoxide, or conversion of the glycol into an alkoxicle, followed by treatment with an organic chloride, such as benzylchloride or allylchloride. It is immaterial how such glycol ethers or ether alcohols are obtained.

Previous reference has been made to' the use of certain monohydric compounds as initial raw materials. Examples are aliphatic -alcohols such as methyl, ethyl, butyl alcohol, and the like, particularly glycol ethers obtained by treating methyl, ethyl or isopropyl and normal butyl alcohol with 1, 2 or 3, or more moles of propylene oxide. Needless to say, these products are equally satisfactory as starting materials and it simply means that the oxypropylation step is shortened.

For that matter similar materials are obtainable commercially such as certain low molal methoxy polyethyleneglycols as illustrated by ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol ethylbutyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, or diethylene glycol monobutyl ether.

Similarly, products could be obtained from butylene oxide except for the expense of this reagent or from a mixture of ethylene and propylene oxide. Obviously there is a limit to the amount of ethylene oxide that can be present for the reason that the monohydric compound on oxypropylation should become water-insoluble at an actual molecular weight range of 1,000 to 2,000, and in many instances at less than 1,000. Likewise, it is preferable that the compound become kerosene-soluble at an actual molecular weight range of 500 to '700 on up. The presence of more than a few ethylene oxide radicals, of course, prevents water-insolubility and prevents kerosenesolubility. The number present can vary, of course, with the terminal group and a degree of oxypropylation but in most cases would be comparatively small, i. e., less than 10 per molecule. In most cases, however, one might as well start with the initial'monohydric material and subject it to oxypropylation.

'For a number of well known reasons equipment, whether laboratory size, semi-pilot plantv size, pilot plant size, or large scale size, is not as a rule designed for a particular alkylene oxide. Invariably and inevitably, however, or particularly in the case of laboratory equipment and pilot plant size the design is such as to use any of the customarily available alkylene oxide, i. e., ethylene oxide, propylene oxide, butylene oxide. glycide, epichlorohydrin, styrene oxide, etc. In the subsequent description of the equipment it becomes obvious that it is adapted for oxyethylation as well as oxypropylation.

Oxypropylations are conducted under a Wide variety of conditions, not only in regard to presence or absence of catalyst, and the kind of catalyst, but also in regard to the time of reaction, temperature of reaction, speed of reaction, pressure during reaction, etc. For instance, oxyalkylations can be conducted at temperatures up to approximately 200 C. with pressures in about the same range up to about 200 pounds per square inch. They can be conducted also at temperatures approximating the boiling point of water or slightly above, as for example to 120 C`. Under such circumstances the pressure will be less than 30 pounds per square inch unless some special procedure is employed as is sometimes the case,

to Wit, keeping an atmosphere of inert gas such as nitrogen in the vessel dur-ing the reaction.V

Such low-temperature-low reaction ratel oxypropylations have been described very completely in U. S. Patent No. 2,448,664, to H. R. Fife et al., dated September '7, 1948. Low temperature, low pressure oxypropylations are particularly desirable where the compound being subjected to oxypropylation contains one, two or three points of reaction only, such as monohydric alcohols..Y

glycols and triols.

Since low pressure-low temperature reaction speed oxypropylations require considerable time, for instance, 1 to '7 days of 24 hours to each to complete the reaction, they are conducted as a rule whether on a laboratory scale, pilot plant scale, or large scale, so as to operate automatically. The prior figure of seven days applies especially to large-scale operations. I have used conventional equipment with'two added auto-i trolled procedure was employed.

l`cedure the autoclave was a conventional autof inaticfeatures; (a.) a solenoidcontrolledlvalve which shuts oi the propylene oxide in event that ure lemperalzure gelzs outsidea predetermined and setrange, for instance, 95 to- 120 C., and (b) of reaction is higher, and time ofA reaction is A much` shorter. In such instances such automatic controls are not necessarily used.

Thus, in preparing the various examples I have found kit particularly vadvantageous Ato use laboratory equipment or pilot plant which is designed lto permit continuous oxyalkylation Whether, it becxypropylation or oxyethylation. With certain obvious changes the equipment can be used also to permit voxyalkylation involving the use of glycide where no pressure is involved ex- 1 cept the vapor pressure of a solvent, if any, which may have been used as a diluent.

As previously pointed out the method of using propylene oxide is the same as ethylene oxide.

This point is emphasized only for the reason that the apparatus is so designed and constructed as to use either oxide.

The oxypropylation procedure employed in the Vthe fact that a continuous automatically-conclave made of stainless steel and having a capacity of approximately gallons and a Working This pressure obviously is far beyond any requirement as far as propylene oxide goes unless there is a reaction, of explosive violence'involved due least one connection for introducing the alkylene oxide, such as propylene oxide or ethylene oxide,

. :Ito the bottom ofthe autoclave; along with suitv1 Y In this prooxide in the liquid phase tothe autoclave.

eductor VYtui'oe.-golnglito the c bottom of. the. .corituner so as to permitdischargingy oiftltylene A bomby having a capacity ofabout y60 4pounds was used in connection with the.15gallon.autoclave.

Other conventional equipmentconsists,.of..course, o f the rupture.v disc, pressure-gauge., sight feed glass, thermometer -connection forxnitrogeny for pressuring-bomb, etc.a The bomb was,l placed on a scale during use. The connections between the i bomb and theautoclave wereflexiblenstainless steelhose or-tubing so that continuous Weighings could be made Without` breaking: or.v making any connections. AThis appliesalso to thelfnitrogen line, Ywhich wasvused to pressure the bombreservoir.

To the extent-that it. was required, any

` other usual conventional procedure ori'addtion Whichprovidedrgreater safety was usedfof course,

= such as safety glass protective-screens, etc.

-Attention-isdirected again. to what` hasbeen said previously-in `regard to automatic .controls Which shut off the vpropylene oxide .in event tem- I perature of reaction passes out .ofthe ipredetermined range orif pressure in theautoclavepasses out of predetermined-range.

i With this particular arrangement practically alloxypropylations, become. uniformA in that the reaction temperature washeld .within a few depreparation of the oxyalkylated derivatives has i been uniformly the same, particularly in light of l -sibly 98 C. .-Similarly, the pressure` Washeld at approximately :30=pounds:. within a 5f-pound variation one. way orthe other, but might.V- drop to practically zero, especially-where no, solvent such as xylene `is employed.. The-Speeder reacpressure of one thousand pounds gauge pressure.

tion was comparatively slow.,.under suchconditions as comparedhwith oxyalkylations atv 200 C.- Numerous reactions-were conducted in which l the time-variedvfrom one day (V24 hours) up to Ythree days (72 hours), for completionof'the nal -Y member ofa series. In-some .instances the reactionmay takeplace in. considerablyY less-time,

i. e., 24 hours or less, as far asa vpartial-oxypropylation iscOncernedV:l The-minimumtimerecorded` was about a 3--hour period-in. a-single step.

Reactions indicated as being complete 1 in 10 hoursvnmayihavef-been complete i-na lesser period able devices for both cooling and heating the Y autoclave, such as a cooling jacket,'and, preferf ably, coils in addition thereto, with the jacket so Y:

.arranged that itis suitable forheating with steam or cooling with water and further equipped with Y electrical heating devices.

of course, in essence small-,scale replicas of the usual conventional autoclave used in oxyalkylation procedures. In some instances in explora- Such autoclaves are,

of time in light vof the automatic equipment.

employed. 'lhisapplies also'wherethe reactions were complete in -a shorter period of time, for

instance, 4- to 5 hours.A In the-addition ofpropylene oxideyinthe autoclave equipmentl-as far vaspossilole the-valveswere setvso all the propylene oxide if fedcqntinuouslyfwould be Yadded at a rate so thatthe predetermined amount would-react within the. iirsty15 vhours of the 24- tory preparations an autoclave having a smaller -v ..I,.apacity, for instance, approximately 31/2 liters in one case and about 11i/4 gallons in another case,

.Was used.

4 Continuous operation, or substantially continut ous operation, was achieved by the use of a sepa- 1 .rate-container to hold the alkylene oxide being employed, particularly propylene oxide. In conjunction with the smaller autoclaves, the container consists essentially of a laboratory bomb hour period/for two-thirds of` anyk shorter period. .This meant Y that` if the reaction was. interrupted automatically for a-periodffof-.time .for `pressure to Avdrop or--temperature` .to V.drop vthe predeter- .mined amount of-oxidewould stilLbe .added in most instances 1Well. within the ypredetermined l3,5 timeperiodw Sometimesrwherezthe addition was a comparatively, small amount rin a.-1.0hour period there would be an,:unquestionableispeeding up of the reaction,` by simply repeating the examples and using 3, 4 or 5 hours instead of 10 hours.

.i When operating at a comparatively high temperature, for instance,between 15071150r 200 C., an.A unreacted alkylenel oxideisuchv as i, propylene pressure or theoonsistency, of af-higherf. pressure.

y; oxide. oxypropylate at a modestly higher temperature,

.` :amount of oxide.

However, at a low enough temperature it may is, of course, an inherent danger and appropriate steps must be taken to safeguard against this possibility; if need be a sample must be withdrawn and examined for unreacted'propylene One obvious procedure, of course, is to for instance, at 140 to 150 C. Unreacted oxide affects determination of the acetyl or hydroxyl value of the hydroxylated compound obtained.

The higher the molecular weight of the compound, i. e., towards the latter stages of reaction, the longer the time required to add a given One possible explanation is that the molecule, being larger, the opportunity for random reaction is decreased. Inversely, the lower the molecular weight the faster the reaction takes place. For this reason, sometimes at least, increasing the concentration of the catalyst does not appreciably speed up the reaction, particularly when the product subjected to oxyalkylation has a comparatively high molecular weight. However, as has been pointed out previously, operating at a low pressure and a low temperature even in large scale operations as much as a week or ten days time may lapse to obtain some of the higher molecular weight de- -rivatives from monohydric or dihydric materials.

In a number of operations the counterbalance scale or dial scale holding the propylene oxide bomb was so set that when the predetermined amount of propylene oxide had passed into the reaction the scale movement through a time operating device was set for either one to two hours so that reaction continued for l to 3 hours after the iinal addition of the last propylene oxide and thereafter the operation was shut down.

.This particular device is particularly suitable for use on larger equipment than laboratory size autoclaves, to wit, on semi-pilot plant or pilot plant size, as Well as on large scale size. This final stirring period is intended to avoid the presence of unreacted oxide.

In this sort of operation, of course, the temperature range was controlled automatically by either use of cooling water, steam, or electrical heat, so as to raise or lower the temperature. The pressuring of the propylene oxide into the reaction vessel was Aalso automatic insofar that -the feed stream was set for a slow continuous run which Was shut oil in case lthe pressure passed a predetermined point as previously set out. All the points of design, construction, etc., were conventional including the gases, check valves and entire equipment. As far as I am aware at least two iirms, and possibly three, specialize in autoclave equipment such as I have em- EXAMPLE la The monohydric compound employed was isopropyl alcohol which was substantially anhydrous.

' In the initial oxypropylation this material was reacted with propylene oxide in the ratio of 20 moles of propylene oxide for one mole of the alcohol.

. The'autoclave employed had a capacity 01.15

gallons or about pounds of reaction mass". The speed of the stirrer could be varied from to 350 R. P. M. 3 pounds of isopropyl alcohol was charged into the autoclave along with one pound of sodium hydroxide. The reaction pot was flushed out with nitrogen. The autoclave was sealed and the automatic devices adjusted and set for injecting 58 pounds of propylene oxide in 7 hours with an allowance of another hour for stirring to insure completeness of reaction. The pressure regulator was set for a maximum of 35 pounds per square inch. IThis meant that the bulk of the reaction could take place, and probably did take place, at a comparatively lower pressure. This comparatively low pressure was the result of the fact that considerable catalyst was present. The propylene oxide was added at the rate of about 8 pounds per hour. More important, the selected temperature range was 205 to 215 F. (about the boiling point of water). The initial introduction of propylene oxide was not started until the heating devices had raised the temperature to about the boiling point of water. At the completion of the reaction the molecular weight, based on a hydroxyl value determination, was 723 compared with a theoretical molecular weight of 1220.

The nal product was water-soluble or dispersible in xylene but not soluble in kerosene, or at least the bulk of the compound was not soluble in kerosene.

This batch of 61 pounds, except for a small amount withdrawn as a sample, was divided `into 5 equal portions and subsequently subjected to further oxypropylation as described in Examples 2a to 6a inclusive.

EXAMPLE 2a In this instance a 5-gallon autoclave Was used instead of a 15-gallon autoclave. The equipment and design of the 5-gallon autoclave was the same as that of the l5-gallon autoclave.

The same procedure was employed as in Example la, preceding, except that the initial reactant was 12.2 pounds of the oxypropylated derivative described as Example la., preceding. To this mixture there was added 4 ounces of caustic soda. The time period was approximately 11/2 hours with an added 45 minutes for stirring. v'Ihe amount of oxide added was 11.6 pounds.

The molecular weight, based on hydroxyl value, was 1060, compared with a theoretical molecular weight of 2380.

The conditions of temperature and pressure Were substantially the same as in Example la, preceding. The product was water-insoluble, xylene-soluble and kerosene-soluble. This state- `ment applies also to the next four examples and The same procedure was followed as in Example 2a, preceding, i. e., the initial charge was 12.2 pounds of the product identified as Example 1a, preceding. The amount of propylene oxide added was 23.2 pounds. The amount of alkaline aeoaose,...

catalyst added was 6 ounces, The oxypropyla--v EXAMPLE 4a i The initial-.reactant was the same as in the two preceding Examples A2er-,and 3a, i. e., 12.2

poundsof the product identified as 'ExamplelaaVV precedingfiv The amount of propylene oxide added was `34 pounds. The amount of 'alkaline catalyst employedY was 9.V ounces. The time required to.V add the propylene oxide was 41/2 hours withan allowance of 11/2 hours'for stirring to insure completion of reaction.

The molecular weight, based on hydroxyl number determinationwas 1813 compared with a theoretical ,molecular weight of 4700.

EXAMPLE 5w The samecprocedure was followed as in Examples 2a, ,3a and 4a, preceding. The initial reactant was 12.2 pounds of the material previously identified as Example la.- The amountv of kpropylenefpxide' addedvw'as 46.4"pounds. The

, In the case of butanol the initial reaction iny volved 3.7,pounds of butanol instead of 3 pounds first series, the only difference being as follows:

as inthe case of isopropanol. The initial reaction mass was broken into ve parts of approximately 12.4 pounds each instead of 12.2 pounds uas inthe series labove described. The

amount of oxide added, the amount of catalyst added, the time factor, temperature factor, pressure factor, etc., were all substantiallyidenticall within ability to repeat two series as in the case f of Examples `lathrough 6a.

The sameslight modification applies to Examples 13a. through 18a. In other words 5.1 poundsof hexanol. were employed instead of 3 pounds ofi isopropanol. Similarly, this initial oxypropylation was broken into five parts of approximately, 12.6 pounds each which was em- -I ployed instead of the 12.2 pounds in the rst series, and Y 12.4 pounds in the second series.

f Here again `all the conditions of oxypropylation were substantially thesameA as in series 1a amountof catalyst added was 12 ounces of caus-l i.

tic soda. The time period for introduction of the oxide was 6.1/2 hours and the reaction mass was stirred for another hour to insure completion of reaction.

The final product showed a molecular weight based on hydroxy number of2200 comparedy withv f through 6a., A

Table 1 Molecular Initial Theo- Weight ExampleNo. Monohydric retical Based on Compound Weight Hydroxy! Value 1a Isopropanol. l, 220 723 2a o- 2,380 1, 060 3, 540 1, 570 4, 70o 1, 813 5, 86o 2, 20u 7,020 2, 46o 1,234 695 2, 394 1,010 3, 554 1, 423 4, 714 1,740 5, 874 ,050 7, O34 2, 210 1, 262 73e 2, 422 1, 050 3, 582 1, 51o do 4, 742 l, 620 17a --do.- 5,902 1, 755 18a do A 7, c62 1,985

The same procedure was followed as in Ex-V amplera, preceding. VThe initial reactant was 12.2 -pounds of the product identified asExample la, preceding. The amount of propylene oxide Although caustic soda was used in the above oxypropyla-tion needless to say any other suitable catalyst, such as sodium-methylate, caustic potash, or the like, could have been employed .Y

l equally satisfactorily.

addedwas fpounds. The amount of catalyst was onepoundof caustic soda. The ,propylene oxide was added in 21.17% hour period .with 2.V hoursadded `for stirring to insure completeness of reaction; The molecular weight of the product, based on a hydroxyl value determination, was 2460, and based on a theoretical molecular weight'it was 7020.

The same procedure Was employed in connec-Y Particular reference is made toA comparable Example '7a' derived from butanol and Example 13a derived vfrom hexanol, as noted in following Tablel.l Tableflincludes data in regard to Ex-` amples la through-6a, and alsoA Examples 7a through' v12a derived from N-buta-nol and Examples' 13a through 18o!l derived from N-hexanol.

In the following table all examples wereconducted in'V exactlythe lsame molal ratio `as in the Speaking of insolubility in Wateror solubility in kerosene such solubility test can be made sim-y ply by shaking small amounts of the materials in a test tube with water, for instance, using 1% to 5% approximately based on the amount of water present.

Needless to say, there is no complete conver-` sion of propylene oxide into the desired hydroxylar weights exceed 1,000 or 2,0010. In some instances the acetyl :value or hydroxyl value serves as satisfactorily as -an index to the molecularv y weight as any other. procedure, subject to the@v above limitations, and especially in the higher molecular weight range. If any difficulty is encountered in the manufacture of the esters the stoichiometrical,amountof acid or acid compound lshould' be taken which -correspondsyto` the l indicated acetylor hydroxyl value.` This mattersulte begins to decompose at about 100 C. and this reaction must be conducted at a suitable temperature until the sodium bisulte has combined. Thereafter, the xylene can be distilled over in the usual manner, removing any water with it and all the xylene loan be removed by distillation, particularly vacuum distillation.

The same procedure was followed in connection with a number of additional examples, all of which are illustrated in the following table which gives the reactants, amounts employed, temperature of esteriflcation, etc.

Table 2 K a d M 1 A t A itwx' Efsiter' sod llt/lax RB" in an o m mt. s eri caesc Ex. N o. Wt. of p. p. g. Used l'nx? Used (hlele) ication tion Bstll Ttion @golg Ether Used (grs.) (grs.) (gm) eri). (Hm) Propyl. 2070"-. 311 Maleic Anhyd. 8 50 145 3% 8 80-95 3 Propyl. 770 121 do 8 45 139 4 8 80-95 4% Propyl. 1070--.-- 8 45 142 3% 8 80-95 4% Propyl. 2570 8 60 145 4% 8 80-95 3% Propyl. 1570".-- 8 50 143 4% 8 80-95 3% Propyl. 2070.-.-- 9 50 144 3% 8 80-95 3% Propyl. 770 9 45 139 4 8 80-95 4% Propyl. 1070. 9 45 142 3% 8 80-95 4% PrOpyl. 2570. 9 60 145 4 8 80-95 4 Ptopyl. 1570. 9 50 140 4% 8 80-95 3% Methyl. 2040.--- 8 50 144 3% 8 80-95 3% Methyl. 740 8 45 139 4% 8 80-95 4% Methyl. 1040.--. 8 45 143 3% 8 80-95 4% Methyl. 2540 8 60 145 4 8 80-95 4% Methyl. 1540 8 50 143 4% 8 80-95 3% Methyl. 2040 9 50 144 A 3% 8 80-95 3 Methyl. 740." 9 45 139 4 8 80-95 4% Methyl. 1040" 9 45 140 3% 8 80-95 4% Methyl. 2540.--- 9 60 145 4 8 80-95 4 Methyl. 1540- 9 50 142 4% 8 80-95 4 regard to the methyl ethers and the propyl ethers. The procedure is illustrated by the following example.

EXAMPLE 1b In a reaction flask there were placed 8 grams of maleic anhydride, 311 grams of the propyl ether of a polypropylene glycol corresponding to polypropylene glycol 2025. The molal ratio was two moles of the glycol ether to one mole of the anhydride. Approximately 1% of toluene sulfonic acid was added, based on the weight of the glycol ether. In this instance three grams of the sulfonic acid were used. There was added also 50 cc. of xylene. Heat was applied and refluxing permitted to continue for about 3% hours. The maximum temperature during the reflux period was approximately 145 C. The amount of water which distilled over was about 1 cc. At the end of the reaction period there Was still a slight acidity due to the uncombined maleic acid radicals and the presence of the acid catalyst. A small amount of aqueous caustic soda was added until suflicient had been introduced to neutralize the acidity present. After this `adjustment, 8 grams of powdered sodium bisulte were added. Apparently enough water had been added to dissolve at least part of the sodium bisulte so that further addition of water was not required. Needless to say, if no caustic soda solution was added to neutralize the acidity, then a little Water should be added to dissolve at leastpart or all of the sodium bisulflte so as to give a saturated solution. The reaction mixture was stirred and heated for three hours. No further effort was made to have any reflux take place during this stage of the reaction for the obvious reason that if water were removed and if sodium bisulfite were anhydrous there Would be little or no opportunity for a reaction period. This is also necessary for the reason that sodium bi- In the above table the kind of ether is indicated by the characterizing radical, i. e., vpropyl or methyl. The actual ether alcohol was, of course, the corresponding polypropylene glycol ether, i. e., either the propyl ether or the methyl ether and the figure indicates the molecular weight which in a general way corresponds to molecular Weight of available polypropylene glycols, i. e., polypropylene glycol 20.25, polypropylene glycol 725, polypropylene glycol 1025, polypropylene glycol 2525, and polypropylene glycol 1525. As previously pointed out these ethers, and for that matter the corresponding glycols, represent cogenericmixtures Whose statistical average molecular weights are the particular weights indicated. Reference in the table is, of course, to the hydroxyl value molecular weight for the obvious reason that this is the basis for calculating the amount of reactants required.

In all instances a small amount of 30% caustic soda solution was used as in the more complete description of Example 1b, and also an amount of toluene sulfonic acid approximating 1% of the weight of the glycol ether, or slightly less, was used in the esterication step. A larger amount should not be used because there may be decomposition of the glycol ether. Smaller amounts can be used, for example, 1/2% or based on the amount of glycol ether provided, however, that the esterication time is extended.

The products obtained are comparable to the initial glycol ether in appearance, etc., i. e., usually they are an amber color or at least of a slight straw color, and often somewhat thicker than the original glycol ether. This description applies of course, to materials after the removal of the solvent, i. e., the xylene. For use as demulsiers there is no need to remove the xylene and it may remain behind. Obviously other liquids than xylene may be used in esterication procedure.

13 However; nif the boilingcomme-ainynignerftha'n xylene there is dangerthat decomposition may y' f 1 take place unless the amount'of sulfonicacidfisfreduced. Other catalysts such as a small amount 'v of dry'hydrochloric acid can beV used but it"'ap `4 5 pears less desirable than the sulfonic a'cidj Need# less to'say, the caustic soda solution used; neuVv tralizes ,the sulfonic acid catalyst present.' The equipment used in esterication procedure; is a resin' pot of the kind described in'U.Pat l0 ent ,Non 2,499,370, dated March 7, 1 950, tojDe Groote and Keiser. Anyconventional'equipment can b'eusecL either on a small scale, pilot plant i scalefor larger'scale. In theyarious examples preceding onlysone 15' glycol 'ether has been used in 'these cases." ActualY` ly there is no reason Vwhy Vone may'notuse two'Y different glycol ethers, for instance, an equimolar mixture of two glycol ethers, one for example having a molecular Weight of 2000 and the other 3000; or one having a molecular weight of 1500 and the other 2500. Actually these glycol ethers are cogeneric mixtures at each selected molecular weight. If one does make a mixture of the kind here described actually three types of compounds will appeal', one type in which both carboxyl radicals ofthe polycarboxy acid are joined with thehigher glycol ether, one type where both carboxyls are joined with the lower molecular" weight glycol ether, and one type where one carl" 30 boxylis Y united to a higher molecular weight glycolgetherfand the other one to a lower molecular4 weight glycol ether.

Other variations are obviously possible' by`using d'i'ierent radicals in the ether positions, su ch as methyl glycol ethers or propyl glycol ethers. For example', the saine dicarboxy'reacta'nt can be used; such as maleic anhydrid'e'united with diier'ent ethers of the saine glycoljfor' instance, the two previously mentioned, or the diierentfgo ether groups might be joined toglycol of different molecular weights.

The products so obtained are peculiar (a) insofar that there is lnot present any radical having 8 or more uninterruptedcarbon atoms, and .5 (b) the compounds are not particularly effective" as surface-active agents in the ordinary sense due either to the large molecular size or-the absence of a hydrophobe radical of the kindpreviously referred to, or Afor some other reason which s o b 50 scure. The chemical compounds herein employed as demulsiiiers have molecular weights varying from more than 1000 up to several thousands, f or instance, 5000, 6000, or '7C-00, and yetcontain only7 one 'sulfo radical. Utility of such compounds for industrial uses is rather unusual. They are not effective emulsifying agents, but are valuableas an additive or a promoter of emulsions. These compounds also have hydrotropic property and serve as common solvents in the preparation of micellar solutions. It is to be noted that they are free from terminal carboxyl radicals and thus differ from reagents obtained, for example, by treating" one Ymole of a high molal polypropylene glycol with 2 moles of a dicarboxy acid. It is probable these reagents, due to their "peculiar structure and their peculiar solubility characteristic's; will iind utility inothereldsof appliciaf tion'now' unknown.

Conventional demulsifying agentsV employed'in 70 the teatmentof oil-field emulsions' are usedas such,`-"or after dilution with anysuitable solvent, suchaswatenpetroleum hydrocarbons, such as benzene toluene,- xylene,` tar 'acid `oil, cresolg" anthracene oil, etc. Alcohols, particularly ali- 75 phatic alcohols', such as-'methyl -alcoholj ethyl a'l-4 cohol'gjdenatured-alcohol, propyl alcohol, butylal` *f cohol,'hexylfalcoholy'octyl alcoholyetcs may be employed as diluents. Miscellaneous? solventsl suchas vpine oil, carbon tetrachloride', sulfur dioxide extract obtained inthe refining of petroleum', etc., may be employed as diluents. Similar-y ly, the material or'materials employed as the de` in connection with conventional demulsifying agents;Vv Moreover, said'material or materials may be used alone erin admixture with other suite able well-known classes 'of'demulsifyingagents.

It is well known that conventional'demulsify`v ing agents may be used in a water-soluble'fori'r'i,v or in-an-oil-soluble form, or in a form exhibiting# botnoilandwatersolubility.' Sometimes they mayfbe'used ina form which exhibits relatively" limited"oil-solubility! fIjIoWever, since such reagents are frequently used'in a ratio of'l to 10,000l or 1 to 20,000, or v1 to 80,000, or even4 l to 40,000,0'r

1 to 50,000 asin desalting practice, xsuch an apparent vinsolubility in oil and Water is not-signifieV 'l cant because saidreagents undoubtedly have sol'ui' bility Within such concentrations. This-same fact is truel inf regard to the material or materials e`m ployed'asthe demulsifying agent of'my process.-

In practicing my process for resolving petr'o-f leum'einulsins' of the water-in-oil type, a treat'- 1 ing agent'or demulsifying agent of the kindfabove-v l described is brought into contact with orcaused to act upon tlie emulsion to bev treatedyini any of the various apparatus now generally usedto resolve or break petroleum 'emulsions with ay chemical reagent, the above procedure beingused" alone orincombination with other demulsifying procedure, such as the electrical dehydration process.

One type'of procedure'is to accumulate a v01` ume of emulsied oil in a tank and conduct a batch treatment type of demulsication procedure to recover clean oil. In this procedure theV emulsion is admixed with the demulsifier, for example by'agitating the tank of emulsion and slowly dripping demulsifler into the emulsion. v In some cases' mixing is achieved by heating the emulsion while dripping in the demulsifier, de-

pending upon the convection currents in the emulsion to produce satisfactory admixture. In

a third modification of this type of treatment, a'

circulating pump withdraws emulsion from, e. g., the bottom of the tank, and reintroduces it into the top of the tank, the demulsifier being added,`

for example, at the suction side of said circulating pump.

In a second type of treating procedura'th'e demul'sifler is introduced into the well fluids at the well-header at some point between the well-head and the finalV oil storage tank, by means of an adjustable i proportioning mechanism or propor' Ordinarily the ilow of fluids'v through the subsequent lines and fittings suflicesVVV to produce'the desired degree of mixing of def niulsifier 'and emulsion, although in some intioning pump.

stances additional mixing devicesy may'be in"-- 15 mulsier either periodically or continuously in diluted or undiluted form into the well and to allow it to come to the surface with the well uids,

` and then to flow the chemicalized emulsion through any desirable surface equipment, such as employed in the other treating procedures. This particular type of application is decidedly useful when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

In all cases, it will be apparent from the foregoing description, the broad process consists simply in introducing a relatively small proportion of demulsier into a relatively large proportion of emulsion, admixing the chemical and emulsion either through natural flow or through special apparatus, with or without the application Vof heat, and allowing the mixture to stand quiescent until the undesirable water content of the emulsion separates and settles from the mass.

The following is a typical installation.

A reservoir to hold the demulsier of the kind described (diluted or undiluted) is placed at vthe well-head where the eilluent liquids leave the well. This reservoir or container, which may vary from gallons to 50 gallons for convenience, is connected to a proportioning pump which injects the demulsier drop-wise into the fluids leaving the-well. Such chemicalized fluids pass through the :llowline into a settling tank. The settling tank consists of a tank of any convenient size, for instance, one which will hold amounts of fluid produced in 4 to 24 hours (500 barrels to 2000 barrels capacity), and in which there is a perpendicular conduit from the top of the tank to almostv the very bottom so as to permit the incoming fluids to pass from the top of the settling tank to the bottom, so that such incoming iluids do not disturb stratification which takes place during the course of demulsication. The settling tank has two outlets, one being below the Water level to drain olf the water resulting from demulsicaticn or accompanying the emulsion as free water, the other being an oil outlet at the top to permit the passage of dehydrated oil to a second tank, being a storage tank, which holds pipeline or dehydrated oil. If desired, the conduit or pipe which serves to carry the fluids from the Well to the settling tank may include a section of pipe with baffles to serve as a mixer, to insure thorough distribution of the demulsier throughout the fluids, or a heater forvraising the temperature of the uids to some convenient temperature, for instance, 120 to 160 F., or bothy heater and mixer.

Demulsication procedure is started by simply setting the pump so as to feed a comparatively large ratio of demulsier, for instance, 125,000. As soon as a complete break or satisfactory demulsication is obtained, the pump is regulated until experience shows that the amount of demulsier being added is just suicient to produce clean or dehydrated oil. The amount being fed at such stage is usually 1:10,000, 1115,000, 1 :20,000, or the like.

In many instances the products herein specified as demulsiers can be conveniently used without dilution. However, as previously noted, they may be diluted as desired with any suitable solvent. Forfinstance, by mixing 75 partsl by Weight of such' derivative, for example, the product of Example 4b with 15 parts by Weight of xylene and parts by weight of isopropyl alcohol, an excellent demulsier is obtained. Selection of the 16 solvent will vary, depending upon the solubility characteristics of the product, and of course will be dictated in part by economic considerations, i. e., cost.

As noted above, the products herein described may be used not only in diluted form, but also may be used admixed with some other chemical demulsifier.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A process for breaking petroleum emuslions of the water-in-oil type characterized bysubjecting the emulsion to the action of a demulsier including hydrophile synthetic products; said hydrophile synthetic products being characterized by the following formula:

in which lait is the divalent radical of an unsaturated dicarboxy acid selected from the class consisting of maleic acid, fumaric acid, and citraconic acid, and n is a whole number varying from 12 to 80; R is a hydrocarbon radical having less than 8 carbon atoms; and with the further proviso that the corresponding polypropylene glycol ether of the formula RO(C3H5O)H be water-insoluble and kerosene-soluble.

2. The processof claim 1 wherein the dicarboxy acid is maleic acid.

3. The process of claim 1 wherein the dicarboxy acid is maleic acid and the value of n corresponds to a polypropylene glycol of approximately 700 molecular weight.

4. The process of claim l wherein the dicarboxy acid is maleic acid and the value of n corresponds to a polypropylene glycol of approximately 1000 molecular weight.

5. The process of claim 1 wherein the dicarbOxy acid is maleic acid and the value of n corresponds to a polypropylene glycol of approximately 1500 molecular weight.

6. The process of claim 1 wherein the dicarboxy acid is maleic acid and the value of n corresponds to a polypropylene glycol of approximately 2000 molecular weight.

7. The process of claim l wherein the dicarboxy acid is maleic acid and the value of n corresponds to a polypropylene glycol of approximately 2500 molecular weight.

MELV'lN DE GROOTE.

`REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,072,085 De Groote et al. Mar. 2, 1937 2,184,794 De Groote Dec. 26, 1939 2,301,609 Bonnet Nov. 10, 1942 2,305,067 De Groote Dec. 15, 1942 2,315,375 Nawiasky et al. Mar. 30,v 1943 2,353,694 De Groote July 18, 1944 Y 2,514,399 Kirkpatrick et al. July 1l, 1950 

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPE CHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIER INCLUDING HYDROPHILE SYNTHETIC PRODUCTS; SAID HYDROPHILE SYNTHETIC PRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA: 